In the food art, particularly in relation to the packaging of roast and ground coffee and roasted whole beans, it is essential that the foodstuff prior to being packaged undergo a degassing technique. When coffee is packaged in a flexible, plastic-type container without first being degassed, the package will balloon as evolved carbon dioxide is liberated from the coffee and eventually the container will break and its contents will be ruined. Even in the event that the package does not rupture, the evolved gasses will create an expansion of the package that will render the package unattractive from a consumer standpoint.
The food art, in response to this problem has developed a number of degassing procedures. However all the degassing procedures suffer from certain problems. The problems include expensive processing costs, specific problems associated with ingredients such as Robusta coffees which are slow to degas resulting in a limited use level of the ingredient and problems of freshness caused by long holdup periods necessitated by the degassing procedure. Should large quantities of Robusta coffees be included in the coffee formula, a more elaborate degassing procedure is necessary which will amplify the above-mentioned adverse effects. Because of the disadvantages of degassing, there has been a need to circumvent degassing by developing a substance which could be added to the food product to remove the evolved gasses which remain in a food product which has not been degassed prior to packaging.
British Pat. No. 1,579,460 entitled "Oxygen Absorbents" teaches the production of an agent for absorbing or removing oxygen comprising iron and at least one metal halide, characterized in that the iron contains sulfur in an amount of from 0.05 to 5% based on the weight of the iron. This specification and the prior art cited therein center upon the problem of selectively removing oxygen from the atmosphere in which the foodstuffs are packaged, thereby preserving the packaged foodstuffs by preventing oxidation and spoilage.
U.S. Pat. NO. 4,366,179 issued to Nawata et al. entitled "Oxygen And Carbon Dioxide Absorbent And Process For Storing Coffee By Using the Same" teaches an oxygen and carbon dioxide sorbent to be packaged with roast and ground coffee or roasted whole coffee beans, said sorbent comprising a particulate substance wherein the particles of a hydrous alkali substance are covered with separator particles, iron powder and an electrolyte. The hydrous alkali substance is a particulate alkaline earth metal hydroxide impregnated with water or a moisture-conditioning solution, or a particulate carrier of low water solubility which is impregnated with water or a moisture-conditioning solution. The alkaline earth hydroxide is either magnesium hydroxide, calcium hydroxide or barium hydroxide. The iron powder functions to absorb oxygen and the electrolyte is a strong electrolytic inorganic salt, preferably a metal halide. The sorbent requires the presence of water or a moisture-conditioning solution which will adjust the relative humidity so that the equilibrium relative humidity of the resulting sorbent is more than 30% and equal to or less than 100%. Also the sorbent must be wrapped in a gas permeable membrane that prevents the escape of water from within the membrane package.
However, in the coffee art the problem of the removal of carbon dioxide from coffee, which has not been completely degassed prior to packaging, remains a problem for which a satisfactory substitute has not been found even though the art has been seeking ways to avoid the degassing procedure.